The present invention relates to an electronic control method and apparatus for a combustion engine, and more particularly to an improvement of a method and apparatus for controlling the combustion of air-fuel mixture in the engine in which a digital computer is employed to control the amount of fuel metered into the combustion chamber of the engine and the timing of sparks supplied to the engine in accordance with changes of the operating condition of the engine.
In a conventional electronic fuel injection control device, rotation speed of a crankshaft and the amount of air supplied to the engine are electrically detected as a main parameter to control the amount of fuel supplied to the engine, meanwhile in a conventional electronic spark timing control device, negative pressure in the intake manifold and rotation speed of a crankshaft are electrically detected as a main parameter to control the timing of sparks supplied to the engine. This means that in the case a digital computer is employed to operate both the fuel injection control device and the spark timing control device, it is required to provide at least three detecting elements for detecting changes of the operating condition of the engine.